Hurricane Season Highlights Dangers from Rising Seas

Today marks the beginning of hurricane season, a six-month period in which most of the United States’ hurricanes and tropical storms occur. Of course, the east coast of Florida got the party started early this past Memorial Day weekend, hosting tropical storm Beryl with its 10 inches of rain and maximum sustained wind speed of 70 mph, just one in a series of extreme weather events that took place over the holiday weekend. Beryl is especially significant because it is the largest tropical storm to reach land before the official start of hurricane season on June 1st.

“I hope this is not a sign of things to come,” commented U.S. Senator Bill Nelson, alluding to the nine to fifteen named storms, including four to eight hurricanes, NOAA’s forecasters predict will appear between now and the end of the season on November 30. Unfortunately for all of us, the future doesn’t look terribly rosy.

As dramatic as NOAA’s hurricane predictions may sound, the agency is saying that they constitute a “near normal” hurricane season which will be less severe than recent years. Still, it’s worth noting that any hurricane will bring strong winds, heavy rains, and flooding, and it only takes one massive storm to wreak major havoc.

More troubling still is that hurricane and tropical storm-related flooding this year and in the future will be exacerbated by the effects of rising seas. In the past hundred and fifty years sea levels have risen 8 inches and scientists estimate that they will rise between one and seven feet by the end of the century. With recent reports of melting ice sheets in Antarctica and rapidly disappearing glaciers due to climate change, and emerging concern about the role of increased use of water previously locked up in underground aquifers, predictions on the high end are becoming increasingly likely.

A four foot rise in sea level could endanger 5 million residents living in 2.6 million homes on $500 billion of residential real estate in the U.S., not to mention 300 energy-producing facilities, airports, thousands of miles of roads and numerous other types of infrastructure, making them increasingly vulnerable to increased storm surges and flooding.

At a Senate Hearing on the “Impacts of Rising Sea Levels on Domestic Infrastructures” in April, Dr. Ben Strauss of Climate Central warned that rising seas would “raise the launch pad for coastal storm surges,” more than tripling the odds of what used to be “once in a century floods” within the next two decades.

Wind and high waves spun by hurricanes and tropical storms can generate massive storm surges, sometimes flooding large portions of cities and often damaging homes and infrastructure. Beryl’s storm surge and rains have caused many roads in coastal North Carolina to flood, some with as much as three and a half feet of water.

In addition, modern hurricanes will be even more damaging due to bigger deluges. Warming oceans mean that more water vapor is lurking in the air off the coasts, and a 4% increase in water vapor over oceans has been observed since the 1970s. Extra water vapor invigorates storms formed off the coast, meaning that hurricanes and tropical storms will dump greater amounts of rain in their wake. So in addition to rising seas, flooding from hurricanes will become more severe because of greater downpours.

Republican lawmakers in North Carolina are attempting to address the dangers of sea level rise by — almost literally — sticking their heads in the sand. Despite the recent evidence of the damaging effects of hurricanes and coastal flooding in their own state, they are circulating a bill that would reduce state agencies’ ability to calculate future sea level rise by not permitting scientists to “include scenarios of accelerated rates of sea level rise” in making their predictions. In other words, ignore the problem, and the problem is solved!

Good luck selling that one to homeowners on the Outer Banks next time a hurricane bears down on them.

— Erin Gustafson is an Energy and Environmental Policy intern with the Center for American Progress